This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Plasmodium, causative agents of malaria, exhibit cell traversal activity as a prelude to an obligatory developmental stage in hepatocytes and onset of malarial symptoms. Disruption of the Sporozoite Protein Essential for Cell Traversal-1 (SPECT1) gene in the early infection stage of Plasmodium (sporozoite) decreases cell traversal activity and reduces hepatocyte infection. Thus SPECT1 is a potential target for vaccine development. Here we propose to assist with malarial vaccine development and determining the molecular mechanism of SPECT1 function by solving its x-ray crystal structure.